Thermodynamic equilibrium theory-guided design and synthesis of Mg-doped LiFe_(0.4)Mn_(0.6)PO_(4)/C cathode for lithium-ion batteries  

作　　者：Wei Lyu Wenlong Cai Tuan Wang Xiaobo Sun Enhao Xu Jinxuan Chen Kaipeng Wu Yun Zhang 

机构地区：[1]College of Materials Science and Engineering,Sichuan University,Chengdu 610064,Sichuan,China

出　　处：《Journal of Energy Chemistry》2024年第4期619-627,共9页能源化学（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(No.51904250);the China Postdoctoral Science Foundation(No.2021M692254);the Sichuan Science and Technology Program(No.2022YFG0098);the Fundamental Research Funds for the Central Universities(Nos.2021CDSN-02,2022SCU12002,2022CDZG-17,2022CDSN-08,2022CDZG-9);the Hohhot Science and Technology Program(No.2023-Jie Bang Gua Shuai-Gao-3)。

摘　　要：Mn-rich LiFe_(1-x)Mn_(x)PO_(4)(x>0.5),which combines the high operation voltage of LiMnPO_(4)with excellent rate performa nce of LiFePO4,is hindered by its sluggish kinetic properties.Herein,thermodynamic equilibrium analysis of Mn^(2+)-Fe^(2+)-Mg^(2+)-C_(2)O_(4)^(2-)-H_(2)O system is used to guide the design and preparation of insitu Mg-doped(Fe_(0.4)Mn_(0.6))_(1-x)Mg_(x)C_(2)O_(4)intermediate,which is then employed as an innovative precursor to synthesize high-performance Mg-doped LiFe_(0.4)Mn_(0.6)PO_(4).It indicates that the metal ions with a high precipitation efficiency and the stoichiometric precursors with uniform element distribution can be achieved under the optimized thermodynamic conditions.Meanwhile,accelerated Li+diffusivity and reduced charge transfer resistance originating from Mg doping are verified by various kinetic characterizations.Benefiting from the contributions of inherited homogeneous element distribution,small particle size,uniform carbon layer coating,enhanced Li+migration ability and structural stability induced by Mg doping,the Li(Fe_(0.4)Mn_(0.6))_(0.97)Mg_(0.03)PO_(4)/C exhibits splendid electrochemical performance.

关 键 词：(Fe_(0.4)Mn_(0.6))_(1-x)MgxC_(2)0_(4) precursors Thermodynami cequilibrium CO-PRECIPITATION Mg doping Lithium-ion batteries 

分 类 号：TM912[电气工程—电力电子与电力传动] O642.4[理学—物理化学]